The importance of tolerance analysis to the success of a product and show how CETOL 6σ and GD&T Advisor can: ensure the design will perform as expected; help the engineer understand where to focus changes that maximize the benefit on critical design characteristics; manage the impact of variation through all phases of the product lifecycle within the same CAD systems used to manage the design; clearly communicate key design characteristics to others; ensure that the language for describing permissible variation, i.e. GD&T, is applied correctly and completely